xref: /openbmc/linux/drivers/hwmon/lm90.c (revision 3557b3fd)
1 /*
2  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
3  *          monitoring
4  * Copyright (C) 2003-2010  Jean Delvare <jdelvare@suse.de>
5  *
6  * Based on the lm83 driver. The LM90 is a sensor chip made by National
7  * Semiconductor. It reports up to two temperatures (its own plus up to
8  * one external one) with a 0.125 deg resolution (1 deg for local
9  * temperature) and a 3-4 deg accuracy.
10  *
11  * This driver also supports the LM89 and LM99, two other sensor chips
12  * made by National Semiconductor. Both have an increased remote
13  * temperature measurement accuracy (1 degree), and the LM99
14  * additionally shifts remote temperatures (measured and limits) by 16
15  * degrees, which allows for higher temperatures measurement.
16  * Note that there is no way to differentiate between both chips.
17  * When device is auto-detected, the driver will assume an LM99.
18  *
19  * This driver also supports the LM86, another sensor chip made by
20  * National Semiconductor. It is exactly similar to the LM90 except it
21  * has a higher accuracy.
22  *
23  * This driver also supports the ADM1032, a sensor chip made by Analog
24  * Devices. That chip is similar to the LM90, with a few differences
25  * that are not handled by this driver. Among others, it has a higher
26  * accuracy than the LM90, much like the LM86 does.
27  *
28  * This driver also supports the MAX6657, MAX6658 and MAX6659 sensor
29  * chips made by Maxim. These chips are similar to the LM86.
30  * Note that there is no easy way to differentiate between the three
31  * variants. We use the device address to detect MAX6659, which will result
32  * in a detection as max6657 if it is on address 0x4c. The extra address
33  * and features of the MAX6659 are only supported if the chip is configured
34  * explicitly as max6659, or if its address is not 0x4c.
35  * These chips lack the remote temperature offset feature.
36  *
37  * This driver also supports the MAX6646, MAX6647, MAX6648, MAX6649 and
38  * MAX6692 chips made by Maxim.  These are again similar to the LM86,
39  * but they use unsigned temperature values and can report temperatures
40  * from 0 to 145 degrees.
41  *
42  * This driver also supports the MAX6680 and MAX6681, two other sensor
43  * chips made by Maxim. These are quite similar to the other Maxim
44  * chips. The MAX6680 and MAX6681 only differ in the pinout so they can
45  * be treated identically.
46  *
47  * This driver also supports the MAX6695 and MAX6696, two other sensor
48  * chips made by Maxim. These are also quite similar to other Maxim
49  * chips, but support three temperature sensors instead of two. MAX6695
50  * and MAX6696 only differ in the pinout so they can be treated identically.
51  *
52  * This driver also supports ADT7461 and ADT7461A from Analog Devices as well as
53  * NCT1008 from ON Semiconductor. The chips are supported in both compatibility
54  * and extended mode. They are mostly compatible with LM90 except for a data
55  * format difference for the temperature value registers.
56  *
57  * This driver also supports the SA56004 from Philips. This device is
58  * pin-compatible with the LM86, the ED/EDP parts are also address-compatible.
59  *
60  * This driver also supports the G781 from GMT. This device is compatible
61  * with the ADM1032.
62  *
63  * This driver also supports TMP451 from Texas Instruments. This device is
64  * supported in both compatibility and extended mode. It's mostly compatible
65  * with ADT7461 except for local temperature low byte register and max
66  * conversion rate.
67  *
68  * Since the LM90 was the first chipset supported by this driver, most
69  * comments will refer to this chipset, but are actually general and
70  * concern all supported chipsets, unless mentioned otherwise.
71  *
72  * This program is free software; you can redistribute it and/or modify
73  * it under the terms of the GNU General Public License as published by
74  * the Free Software Foundation; either version 2 of the License, or
75  * (at your option) any later version.
76  *
77  * This program is distributed in the hope that it will be useful,
78  * but WITHOUT ANY WARRANTY; without even the implied warranty of
79  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
80  * GNU General Public License for more details.
81  *
82  * You should have received a copy of the GNU General Public License
83  * along with this program; if not, write to the Free Software
84  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
85  */
86 
87 #include <linux/module.h>
88 #include <linux/init.h>
89 #include <linux/slab.h>
90 #include <linux/jiffies.h>
91 #include <linux/i2c.h>
92 #include <linux/hwmon.h>
93 #include <linux/err.h>
94 #include <linux/mutex.h>
95 #include <linux/of_device.h>
96 #include <linux/sysfs.h>
97 #include <linux/interrupt.h>
98 #include <linux/regulator/consumer.h>
99 
100 /*
101  * Addresses to scan
102  * Address is fully defined internally and cannot be changed except for
103  * MAX6659, MAX6680 and MAX6681.
104  * LM86, LM89, LM90, LM99, ADM1032, ADM1032-1, ADT7461, ADT7461A, MAX6649,
105  * MAX6657, MAX6658, NCT1008 and W83L771 have address 0x4c.
106  * ADM1032-2, ADT7461-2, ADT7461A-2, LM89-1, LM99-1, MAX6646, and NCT1008D
107  * have address 0x4d.
108  * MAX6647 has address 0x4e.
109  * MAX6659 can have address 0x4c, 0x4d or 0x4e.
110  * MAX6680 and MAX6681 can have address 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b,
111  * 0x4c, 0x4d or 0x4e.
112  * SA56004 can have address 0x48 through 0x4F.
113  */
114 
115 static const unsigned short normal_i2c[] = {
116 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x48, 0x49, 0x4a, 0x4b, 0x4c,
117 	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
118 
119 enum chips { lm90, adm1032, lm99, lm86, max6657, max6659, adt7461, max6680,
120 	max6646, w83l771, max6696, sa56004, g781, tmp451 };
121 
122 /*
123  * The LM90 registers
124  */
125 
126 #define LM90_REG_R_MAN_ID		0xFE
127 #define LM90_REG_R_CHIP_ID		0xFF
128 #define LM90_REG_R_CONFIG1		0x03
129 #define LM90_REG_W_CONFIG1		0x09
130 #define LM90_REG_R_CONFIG2		0xBF
131 #define LM90_REG_W_CONFIG2		0xBF
132 #define LM90_REG_R_CONVRATE		0x04
133 #define LM90_REG_W_CONVRATE		0x0A
134 #define LM90_REG_R_STATUS		0x02
135 #define LM90_REG_R_LOCAL_TEMP		0x00
136 #define LM90_REG_R_LOCAL_HIGH		0x05
137 #define LM90_REG_W_LOCAL_HIGH		0x0B
138 #define LM90_REG_R_LOCAL_LOW		0x06
139 #define LM90_REG_W_LOCAL_LOW		0x0C
140 #define LM90_REG_R_LOCAL_CRIT		0x20
141 #define LM90_REG_W_LOCAL_CRIT		0x20
142 #define LM90_REG_R_REMOTE_TEMPH		0x01
143 #define LM90_REG_R_REMOTE_TEMPL		0x10
144 #define LM90_REG_R_REMOTE_OFFSH		0x11
145 #define LM90_REG_W_REMOTE_OFFSH		0x11
146 #define LM90_REG_R_REMOTE_OFFSL		0x12
147 #define LM90_REG_W_REMOTE_OFFSL		0x12
148 #define LM90_REG_R_REMOTE_HIGHH		0x07
149 #define LM90_REG_W_REMOTE_HIGHH		0x0D
150 #define LM90_REG_R_REMOTE_HIGHL		0x13
151 #define LM90_REG_W_REMOTE_HIGHL		0x13
152 #define LM90_REG_R_REMOTE_LOWH		0x08
153 #define LM90_REG_W_REMOTE_LOWH		0x0E
154 #define LM90_REG_R_REMOTE_LOWL		0x14
155 #define LM90_REG_W_REMOTE_LOWL		0x14
156 #define LM90_REG_R_REMOTE_CRIT		0x19
157 #define LM90_REG_W_REMOTE_CRIT		0x19
158 #define LM90_REG_R_TCRIT_HYST		0x21
159 #define LM90_REG_W_TCRIT_HYST		0x21
160 
161 /* MAX6646/6647/6649/6657/6658/6659/6695/6696 registers */
162 
163 #define MAX6657_REG_R_LOCAL_TEMPL	0x11
164 #define MAX6696_REG_R_STATUS2		0x12
165 #define MAX6659_REG_R_REMOTE_EMERG	0x16
166 #define MAX6659_REG_W_REMOTE_EMERG	0x16
167 #define MAX6659_REG_R_LOCAL_EMERG	0x17
168 #define MAX6659_REG_W_LOCAL_EMERG	0x17
169 
170 /*  SA56004 registers */
171 
172 #define SA56004_REG_R_LOCAL_TEMPL 0x22
173 
174 #define LM90_MAX_CONVRATE_MS	16000	/* Maximum conversion rate in ms */
175 
176 /* TMP451 registers */
177 #define TMP451_REG_R_LOCAL_TEMPL	0x15
178 
179 /*
180  * Device flags
181  */
182 #define LM90_FLAG_ADT7461_EXT	(1 << 0) /* ADT7461 extended mode	*/
183 /* Device features */
184 #define LM90_HAVE_OFFSET	(1 << 1) /* temperature offset register	*/
185 #define LM90_HAVE_REM_LIMIT_EXT	(1 << 3) /* extended remote limit	*/
186 #define LM90_HAVE_EMERGENCY	(1 << 4) /* 3rd upper (emergency) limit	*/
187 #define LM90_HAVE_EMERGENCY_ALARM (1 << 5)/* emergency alarm		*/
188 #define LM90_HAVE_TEMP3		(1 << 6) /* 3rd temperature sensor	*/
189 #define LM90_HAVE_BROKEN_ALERT	(1 << 7) /* Broken alert		*/
190 
191 /* LM90 status */
192 #define LM90_STATUS_LTHRM	(1 << 0) /* local THERM limit tripped */
193 #define LM90_STATUS_RTHRM	(1 << 1) /* remote THERM limit tripped */
194 #define LM90_STATUS_ROPEN	(1 << 2) /* remote is an open circuit */
195 #define LM90_STATUS_RLOW	(1 << 3) /* remote low temp limit tripped */
196 #define LM90_STATUS_RHIGH	(1 << 4) /* remote high temp limit tripped */
197 #define LM90_STATUS_LLOW	(1 << 5) /* local low temp limit tripped */
198 #define LM90_STATUS_LHIGH	(1 << 6) /* local high temp limit tripped */
199 
200 #define MAX6696_STATUS2_R2THRM	(1 << 1) /* remote2 THERM limit tripped */
201 #define MAX6696_STATUS2_R2OPEN	(1 << 2) /* remote2 is an open circuit */
202 #define MAX6696_STATUS2_R2LOW	(1 << 3) /* remote2 low temp limit tripped */
203 #define MAX6696_STATUS2_R2HIGH	(1 << 4) /* remote2 high temp limit tripped */
204 #define MAX6696_STATUS2_ROT2	(1 << 5) /* remote emergency limit tripped */
205 #define MAX6696_STATUS2_R2OT2	(1 << 6) /* remote2 emergency limit tripped */
206 #define MAX6696_STATUS2_LOT2	(1 << 7) /* local emergency limit tripped */
207 
208 /*
209  * Driver data (common to all clients)
210  */
211 
212 static const struct i2c_device_id lm90_id[] = {
213 	{ "adm1032", adm1032 },
214 	{ "adt7461", adt7461 },
215 	{ "adt7461a", adt7461 },
216 	{ "g781", g781 },
217 	{ "lm90", lm90 },
218 	{ "lm86", lm86 },
219 	{ "lm89", lm86 },
220 	{ "lm99", lm99 },
221 	{ "max6646", max6646 },
222 	{ "max6647", max6646 },
223 	{ "max6649", max6646 },
224 	{ "max6657", max6657 },
225 	{ "max6658", max6657 },
226 	{ "max6659", max6659 },
227 	{ "max6680", max6680 },
228 	{ "max6681", max6680 },
229 	{ "max6695", max6696 },
230 	{ "max6696", max6696 },
231 	{ "nct1008", adt7461 },
232 	{ "w83l771", w83l771 },
233 	{ "sa56004", sa56004 },
234 	{ "tmp451", tmp451 },
235 	{ }
236 };
237 MODULE_DEVICE_TABLE(i2c, lm90_id);
238 
239 static const struct of_device_id lm90_of_match[] = {
240 	{
241 		.compatible = "adi,adm1032",
242 		.data = (void *)adm1032
243 	},
244 	{
245 		.compatible = "adi,adt7461",
246 		.data = (void *)adt7461
247 	},
248 	{
249 		.compatible = "adi,adt7461a",
250 		.data = (void *)adt7461
251 	},
252 	{
253 		.compatible = "gmt,g781",
254 		.data = (void *)g781
255 	},
256 	{
257 		.compatible = "national,lm90",
258 		.data = (void *)lm90
259 	},
260 	{
261 		.compatible = "national,lm86",
262 		.data = (void *)lm86
263 	},
264 	{
265 		.compatible = "national,lm89",
266 		.data = (void *)lm86
267 	},
268 	{
269 		.compatible = "national,lm99",
270 		.data = (void *)lm99
271 	},
272 	{
273 		.compatible = "dallas,max6646",
274 		.data = (void *)max6646
275 	},
276 	{
277 		.compatible = "dallas,max6647",
278 		.data = (void *)max6646
279 	},
280 	{
281 		.compatible = "dallas,max6649",
282 		.data = (void *)max6646
283 	},
284 	{
285 		.compatible = "dallas,max6657",
286 		.data = (void *)max6657
287 	},
288 	{
289 		.compatible = "dallas,max6658",
290 		.data = (void *)max6657
291 	},
292 	{
293 		.compatible = "dallas,max6659",
294 		.data = (void *)max6659
295 	},
296 	{
297 		.compatible = "dallas,max6680",
298 		.data = (void *)max6680
299 	},
300 	{
301 		.compatible = "dallas,max6681",
302 		.data = (void *)max6680
303 	},
304 	{
305 		.compatible = "dallas,max6695",
306 		.data = (void *)max6696
307 	},
308 	{
309 		.compatible = "dallas,max6696",
310 		.data = (void *)max6696
311 	},
312 	{
313 		.compatible = "onnn,nct1008",
314 		.data = (void *)adt7461
315 	},
316 	{
317 		.compatible = "winbond,w83l771",
318 		.data = (void *)w83l771
319 	},
320 	{
321 		.compatible = "nxp,sa56004",
322 		.data = (void *)sa56004
323 	},
324 	{
325 		.compatible = "ti,tmp451",
326 		.data = (void *)tmp451
327 	},
328 	{ },
329 };
330 MODULE_DEVICE_TABLE(of, lm90_of_match);
331 
332 /*
333  * chip type specific parameters
334  */
335 struct lm90_params {
336 	u32 flags;		/* Capabilities */
337 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
338 				/* Upper 8 bits for max6695/96 */
339 	u8 max_convrate;	/* Maximum conversion rate register value */
340 	u8 reg_local_ext;	/* Extended local temp register (optional) */
341 };
342 
343 static const struct lm90_params lm90_params[] = {
344 	[adm1032] = {
345 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
346 		  | LM90_HAVE_BROKEN_ALERT,
347 		.alert_alarms = 0x7c,
348 		.max_convrate = 10,
349 	},
350 	[adt7461] = {
351 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
352 		  | LM90_HAVE_BROKEN_ALERT,
353 		.alert_alarms = 0x7c,
354 		.max_convrate = 10,
355 	},
356 	[g781] = {
357 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
358 		  | LM90_HAVE_BROKEN_ALERT,
359 		.alert_alarms = 0x7c,
360 		.max_convrate = 8,
361 	},
362 	[lm86] = {
363 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
364 		.alert_alarms = 0x7b,
365 		.max_convrate = 9,
366 	},
367 	[lm90] = {
368 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
369 		.alert_alarms = 0x7b,
370 		.max_convrate = 9,
371 	},
372 	[lm99] = {
373 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
374 		.alert_alarms = 0x7b,
375 		.max_convrate = 9,
376 	},
377 	[max6646] = {
378 		.alert_alarms = 0x7c,
379 		.max_convrate = 6,
380 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
381 	},
382 	[max6657] = {
383 		.alert_alarms = 0x7c,
384 		.max_convrate = 8,
385 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
386 	},
387 	[max6659] = {
388 		.flags = LM90_HAVE_EMERGENCY,
389 		.alert_alarms = 0x7c,
390 		.max_convrate = 8,
391 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
392 	},
393 	[max6680] = {
394 		.flags = LM90_HAVE_OFFSET,
395 		.alert_alarms = 0x7c,
396 		.max_convrate = 7,
397 	},
398 	[max6696] = {
399 		.flags = LM90_HAVE_EMERGENCY
400 		  | LM90_HAVE_EMERGENCY_ALARM | LM90_HAVE_TEMP3,
401 		.alert_alarms = 0x1c7c,
402 		.max_convrate = 6,
403 		.reg_local_ext = MAX6657_REG_R_LOCAL_TEMPL,
404 	},
405 	[w83l771] = {
406 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
407 		.alert_alarms = 0x7c,
408 		.max_convrate = 8,
409 	},
410 	[sa56004] = {
411 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT,
412 		.alert_alarms = 0x7b,
413 		.max_convrate = 9,
414 		.reg_local_ext = SA56004_REG_R_LOCAL_TEMPL,
415 	},
416 	[tmp451] = {
417 		.flags = LM90_HAVE_OFFSET | LM90_HAVE_REM_LIMIT_EXT
418 		  | LM90_HAVE_BROKEN_ALERT,
419 		.alert_alarms = 0x7c,
420 		.max_convrate = 9,
421 		.reg_local_ext = TMP451_REG_R_LOCAL_TEMPL,
422 	},
423 };
424 
425 /*
426  * TEMP8 register index
427  */
428 enum lm90_temp8_reg_index {
429 	LOCAL_LOW = 0,
430 	LOCAL_HIGH,
431 	LOCAL_CRIT,
432 	REMOTE_CRIT,
433 	LOCAL_EMERG,	/* max6659 and max6695/96 */
434 	REMOTE_EMERG,	/* max6659 and max6695/96 */
435 	REMOTE2_CRIT,	/* max6695/96 only */
436 	REMOTE2_EMERG,	/* max6695/96 only */
437 	TEMP8_REG_NUM
438 };
439 
440 /*
441  * TEMP11 register index
442  */
443 enum lm90_temp11_reg_index {
444 	REMOTE_TEMP = 0,
445 	REMOTE_LOW,
446 	REMOTE_HIGH,
447 	REMOTE_OFFSET,	/* except max6646, max6657/58/59, and max6695/96 */
448 	LOCAL_TEMP,
449 	REMOTE2_TEMP,	/* max6695/96 only */
450 	REMOTE2_LOW,	/* max6695/96 only */
451 	REMOTE2_HIGH,	/* max6695/96 only */
452 	TEMP11_REG_NUM
453 };
454 
455 /*
456  * Client data (each client gets its own)
457  */
458 
459 struct lm90_data {
460 	struct i2c_client *client;
461 	u32 channel_config[4];
462 	struct hwmon_channel_info temp_info;
463 	const struct hwmon_channel_info *info[3];
464 	struct hwmon_chip_info chip;
465 	struct mutex update_lock;
466 	bool valid;		/* true if register values are valid */
467 	unsigned long last_updated; /* in jiffies */
468 	int kind;
469 	u32 flags;
470 
471 	unsigned int update_interval; /* in milliseconds */
472 
473 	u8 config_orig;		/* Original configuration register value */
474 	u8 convrate_orig;	/* Original conversion rate register value */
475 	u16 alert_alarms;	/* Which alarm bits trigger ALERT# */
476 				/* Upper 8 bits for max6695/96 */
477 	u8 max_convrate;	/* Maximum conversion rate */
478 	u8 reg_local_ext;	/* local extension register offset */
479 
480 	/* registers values */
481 	s8 temp8[TEMP8_REG_NUM];
482 	s16 temp11[TEMP11_REG_NUM];
483 	u8 temp_hyst;
484 	u16 alarms; /* bitvector (upper 8 bits for max6695/96) */
485 };
486 
487 /*
488  * Support functions
489  */
490 
491 /*
492  * The ADM1032 supports PEC but not on write byte transactions, so we need
493  * to explicitly ask for a transaction without PEC.
494  */
495 static inline s32 adm1032_write_byte(struct i2c_client *client, u8 value)
496 {
497 	return i2c_smbus_xfer(client->adapter, client->addr,
498 			      client->flags & ~I2C_CLIENT_PEC,
499 			      I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
500 }
501 
502 /*
503  * It is assumed that client->update_lock is held (unless we are in
504  * detection or initialization steps). This matters when PEC is enabled,
505  * because we don't want the address pointer to change between the write
506  * byte and the read byte transactions.
507  */
508 static int lm90_read_reg(struct i2c_client *client, u8 reg)
509 {
510 	int err;
511 
512 	if (client->flags & I2C_CLIENT_PEC) {
513 		err = adm1032_write_byte(client, reg);
514 		if (err >= 0)
515 			err = i2c_smbus_read_byte(client);
516 	} else
517 		err = i2c_smbus_read_byte_data(client, reg);
518 
519 	return err;
520 }
521 
522 static int lm90_read16(struct i2c_client *client, u8 regh, u8 regl)
523 {
524 	int oldh, newh, l;
525 
526 	/*
527 	 * There is a trick here. We have to read two registers to have the
528 	 * sensor temperature, but we have to beware a conversion could occur
529 	 * between the readings. The datasheet says we should either use
530 	 * the one-shot conversion register, which we don't want to do
531 	 * (disables hardware monitoring) or monitor the busy bit, which is
532 	 * impossible (we can't read the values and monitor that bit at the
533 	 * exact same time). So the solution used here is to read the high
534 	 * byte once, then the low byte, then the high byte again. If the new
535 	 * high byte matches the old one, then we have a valid reading. Else
536 	 * we have to read the low byte again, and now we believe we have a
537 	 * correct reading.
538 	 */
539 	oldh = lm90_read_reg(client, regh);
540 	if (oldh < 0)
541 		return oldh;
542 	l = lm90_read_reg(client, regl);
543 	if (l < 0)
544 		return l;
545 	newh = lm90_read_reg(client, regh);
546 	if (newh < 0)
547 		return newh;
548 	if (oldh != newh) {
549 		l = lm90_read_reg(client, regl);
550 		if (l < 0)
551 			return l;
552 	}
553 	return (newh << 8) | l;
554 }
555 
556 /*
557  * client->update_lock must be held when calling this function (unless we are
558  * in detection or initialization steps), and while a remote channel other
559  * than channel 0 is selected. Also, calling code must make sure to re-select
560  * external channel 0 before releasing the lock. This is necessary because
561  * various registers have different meanings as a result of selecting a
562  * non-default remote channel.
563  */
564 static inline int lm90_select_remote_channel(struct i2c_client *client,
565 					     struct lm90_data *data,
566 					     int channel)
567 {
568 	int config;
569 
570 	if (data->kind == max6696) {
571 		config = lm90_read_reg(client, LM90_REG_R_CONFIG1);
572 		if (config < 0)
573 			return config;
574 		config &= ~0x08;
575 		if (channel)
576 			config |= 0x08;
577 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
578 					  config);
579 	}
580 	return 0;
581 }
582 
583 /*
584  * Set conversion rate.
585  * client->update_lock must be held when calling this function (unless we are
586  * in detection or initialization steps).
587  */
588 static int lm90_set_convrate(struct i2c_client *client, struct lm90_data *data,
589 			     unsigned int interval)
590 {
591 	unsigned int update_interval;
592 	int i, err;
593 
594 	/* Shift calculations to avoid rounding errors */
595 	interval <<= 6;
596 
597 	/* find the nearest update rate */
598 	for (i = 0, update_interval = LM90_MAX_CONVRATE_MS << 6;
599 	     i < data->max_convrate; i++, update_interval >>= 1)
600 		if (interval >= update_interval * 3 / 4)
601 			break;
602 
603 	err = i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE, i);
604 	data->update_interval = DIV_ROUND_CLOSEST(update_interval, 64);
605 	return err;
606 }
607 
608 static int lm90_update_limits(struct device *dev)
609 {
610 	struct lm90_data *data = dev_get_drvdata(dev);
611 	struct i2c_client *client = data->client;
612 	int val;
613 
614 	val = lm90_read_reg(client, LM90_REG_R_LOCAL_CRIT);
615 	if (val < 0)
616 		return val;
617 	data->temp8[LOCAL_CRIT] = val;
618 
619 	val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
620 	if (val < 0)
621 		return val;
622 	data->temp8[REMOTE_CRIT] = val;
623 
624 	val = lm90_read_reg(client, LM90_REG_R_TCRIT_HYST);
625 	if (val < 0)
626 		return val;
627 	data->temp_hyst = val;
628 
629 	val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
630 	if (val < 0)
631 		return val;
632 	data->temp11[REMOTE_LOW] = val << 8;
633 
634 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
635 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL);
636 		if (val < 0)
637 			return val;
638 		data->temp11[REMOTE_LOW] |= val;
639 	}
640 
641 	val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
642 	if (val < 0)
643 		return val;
644 	data->temp11[REMOTE_HIGH] = val << 8;
645 
646 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT) {
647 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL);
648 		if (val < 0)
649 			return val;
650 		data->temp11[REMOTE_HIGH] |= val;
651 	}
652 
653 	if (data->flags & LM90_HAVE_OFFSET) {
654 		val = lm90_read16(client, LM90_REG_R_REMOTE_OFFSH,
655 				  LM90_REG_R_REMOTE_OFFSL);
656 		if (val < 0)
657 			return val;
658 		data->temp11[REMOTE_OFFSET] = val;
659 	}
660 
661 	if (data->flags & LM90_HAVE_EMERGENCY) {
662 		val = lm90_read_reg(client, MAX6659_REG_R_LOCAL_EMERG);
663 		if (val < 0)
664 			return val;
665 		data->temp8[LOCAL_EMERG] = val;
666 
667 		val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
668 		if (val < 0)
669 			return val;
670 		data->temp8[REMOTE_EMERG] = val;
671 	}
672 
673 	if (data->kind == max6696) {
674 		val = lm90_select_remote_channel(client, data, 1);
675 		if (val < 0)
676 			return val;
677 
678 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT);
679 		if (val < 0)
680 			return val;
681 		data->temp8[REMOTE2_CRIT] = val;
682 
683 		val = lm90_read_reg(client, MAX6659_REG_R_REMOTE_EMERG);
684 		if (val < 0)
685 			return val;
686 		data->temp8[REMOTE2_EMERG] = val;
687 
688 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH);
689 		if (val < 0)
690 			return val;
691 		data->temp11[REMOTE2_LOW] = val << 8;
692 
693 		val = lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH);
694 		if (val < 0)
695 			return val;
696 		data->temp11[REMOTE2_HIGH] = val << 8;
697 
698 		lm90_select_remote_channel(client, data, 0);
699 	}
700 
701 	return 0;
702 }
703 
704 static int lm90_update_device(struct device *dev)
705 {
706 	struct lm90_data *data = dev_get_drvdata(dev);
707 	struct i2c_client *client = data->client;
708 	unsigned long next_update;
709 	int val;
710 
711 	if (!data->valid) {
712 		val = lm90_update_limits(dev);
713 		if (val < 0)
714 			return val;
715 	}
716 
717 	next_update = data->last_updated +
718 		      msecs_to_jiffies(data->update_interval);
719 	if (time_after(jiffies, next_update) || !data->valid) {
720 		dev_dbg(&client->dev, "Updating lm90 data.\n");
721 
722 		data->valid = false;
723 
724 		val = lm90_read_reg(client, LM90_REG_R_LOCAL_LOW);
725 		if (val < 0)
726 			return val;
727 		data->temp8[LOCAL_LOW] = val;
728 
729 		val = lm90_read_reg(client, LM90_REG_R_LOCAL_HIGH);
730 		if (val < 0)
731 			return val;
732 		data->temp8[LOCAL_HIGH] = val;
733 
734 		if (data->reg_local_ext) {
735 			val = lm90_read16(client, LM90_REG_R_LOCAL_TEMP,
736 					  data->reg_local_ext);
737 			if (val < 0)
738 				return val;
739 			data->temp11[LOCAL_TEMP] = val;
740 		} else {
741 			val = lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP);
742 			if (val < 0)
743 				return val;
744 			data->temp11[LOCAL_TEMP] = val << 8;
745 		}
746 		val = lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
747 				  LM90_REG_R_REMOTE_TEMPL);
748 		if (val < 0)
749 			return val;
750 		data->temp11[REMOTE_TEMP] = val;
751 
752 		val = lm90_read_reg(client, LM90_REG_R_STATUS);
753 		if (val < 0)
754 			return val;
755 		data->alarms = val;	/* lower 8 bit of alarms */
756 
757 		if (data->kind == max6696) {
758 			val = lm90_select_remote_channel(client, data, 1);
759 			if (val < 0)
760 				return val;
761 
762 			val = lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
763 					  LM90_REG_R_REMOTE_TEMPL);
764 			if (val < 0) {
765 				lm90_select_remote_channel(client, data, 0);
766 				return val;
767 			}
768 			data->temp11[REMOTE2_TEMP] = val;
769 
770 			lm90_select_remote_channel(client, data, 0);
771 
772 			val = lm90_read_reg(client, MAX6696_REG_R_STATUS2);
773 			if (val < 0)
774 				return val;
775 			data->alarms |= val << 8;
776 		}
777 
778 		/*
779 		 * Re-enable ALERT# output if it was originally enabled and
780 		 * relevant alarms are all clear
781 		 */
782 		if (!(data->config_orig & 0x80) &&
783 		    !(data->alarms & data->alert_alarms)) {
784 			val = lm90_read_reg(client, LM90_REG_R_CONFIG1);
785 			if (val < 0)
786 				return val;
787 
788 			if (val & 0x80) {
789 				dev_dbg(&client->dev, "Re-enabling ALERT#\n");
790 				i2c_smbus_write_byte_data(client,
791 							  LM90_REG_W_CONFIG1,
792 							  val & ~0x80);
793 			}
794 		}
795 
796 		data->last_updated = jiffies;
797 		data->valid = true;
798 	}
799 
800 	return 0;
801 }
802 
803 /*
804  * Conversions
805  * For local temperatures and limits, critical limits and the hysteresis
806  * value, the LM90 uses signed 8-bit values with LSB = 1 degree Celsius.
807  * For remote temperatures and limits, it uses signed 11-bit values with
808  * LSB = 0.125 degree Celsius, left-justified in 16-bit registers.  Some
809  * Maxim chips use unsigned values.
810  */
811 
812 static inline int temp_from_s8(s8 val)
813 {
814 	return val * 1000;
815 }
816 
817 static inline int temp_from_u8(u8 val)
818 {
819 	return val * 1000;
820 }
821 
822 static inline int temp_from_s16(s16 val)
823 {
824 	return val / 32 * 125;
825 }
826 
827 static inline int temp_from_u16(u16 val)
828 {
829 	return val / 32 * 125;
830 }
831 
832 static s8 temp_to_s8(long val)
833 {
834 	if (val <= -128000)
835 		return -128;
836 	if (val >= 127000)
837 		return 127;
838 	if (val < 0)
839 		return (val - 500) / 1000;
840 	return (val + 500) / 1000;
841 }
842 
843 static u8 temp_to_u8(long val)
844 {
845 	if (val <= 0)
846 		return 0;
847 	if (val >= 255000)
848 		return 255;
849 	return (val + 500) / 1000;
850 }
851 
852 static s16 temp_to_s16(long val)
853 {
854 	if (val <= -128000)
855 		return 0x8000;
856 	if (val >= 127875)
857 		return 0x7FE0;
858 	if (val < 0)
859 		return (val - 62) / 125 * 32;
860 	return (val + 62) / 125 * 32;
861 }
862 
863 static u8 hyst_to_reg(long val)
864 {
865 	if (val <= 0)
866 		return 0;
867 	if (val >= 30500)
868 		return 31;
869 	return (val + 500) / 1000;
870 }
871 
872 /*
873  * ADT7461 in compatibility mode is almost identical to LM90 except that
874  * attempts to write values that are outside the range 0 < temp < 127 are
875  * treated as the boundary value.
876  *
877  * ADT7461 in "extended mode" operation uses unsigned integers offset by
878  * 64 (e.g., 0 -> -64 degC).  The range is restricted to -64..191 degC.
879  */
880 static inline int temp_from_u8_adt7461(struct lm90_data *data, u8 val)
881 {
882 	if (data->flags & LM90_FLAG_ADT7461_EXT)
883 		return (val - 64) * 1000;
884 	return temp_from_s8(val);
885 }
886 
887 static inline int temp_from_u16_adt7461(struct lm90_data *data, u16 val)
888 {
889 	if (data->flags & LM90_FLAG_ADT7461_EXT)
890 		return (val - 0x4000) / 64 * 250;
891 	return temp_from_s16(val);
892 }
893 
894 static u8 temp_to_u8_adt7461(struct lm90_data *data, long val)
895 {
896 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
897 		if (val <= -64000)
898 			return 0;
899 		if (val >= 191000)
900 			return 0xFF;
901 		return (val + 500 + 64000) / 1000;
902 	}
903 	if (val <= 0)
904 		return 0;
905 	if (val >= 127000)
906 		return 127;
907 	return (val + 500) / 1000;
908 }
909 
910 static u16 temp_to_u16_adt7461(struct lm90_data *data, long val)
911 {
912 	if (data->flags & LM90_FLAG_ADT7461_EXT) {
913 		if (val <= -64000)
914 			return 0;
915 		if (val >= 191750)
916 			return 0xFFC0;
917 		return (val + 64000 + 125) / 250 * 64;
918 	}
919 	if (val <= 0)
920 		return 0;
921 	if (val >= 127750)
922 		return 0x7FC0;
923 	return (val + 125) / 250 * 64;
924 }
925 
926 /* pec used for ADM1032 only */
927 static ssize_t pec_show(struct device *dev, struct device_attribute *dummy,
928 			char *buf)
929 {
930 	struct i2c_client *client = to_i2c_client(dev);
931 
932 	return sprintf(buf, "%d\n", !!(client->flags & I2C_CLIENT_PEC));
933 }
934 
935 static ssize_t pec_store(struct device *dev, struct device_attribute *dummy,
936 			 const char *buf, size_t count)
937 {
938 	struct i2c_client *client = to_i2c_client(dev);
939 	long val;
940 	int err;
941 
942 	err = kstrtol(buf, 10, &val);
943 	if (err < 0)
944 		return err;
945 
946 	switch (val) {
947 	case 0:
948 		client->flags &= ~I2C_CLIENT_PEC;
949 		break;
950 	case 1:
951 		client->flags |= I2C_CLIENT_PEC;
952 		break;
953 	default:
954 		return -EINVAL;
955 	}
956 
957 	return count;
958 }
959 
960 static DEVICE_ATTR_RW(pec);
961 
962 static int lm90_get_temp11(struct lm90_data *data, int index)
963 {
964 	s16 temp11 = data->temp11[index];
965 	int temp;
966 
967 	if (data->kind == adt7461 || data->kind == tmp451)
968 		temp = temp_from_u16_adt7461(data, temp11);
969 	else if (data->kind == max6646)
970 		temp = temp_from_u16(temp11);
971 	else
972 		temp = temp_from_s16(temp11);
973 
974 	/* +16 degrees offset for temp2 for the LM99 */
975 	if (data->kind == lm99 && index <= 2)
976 		temp += 16000;
977 
978 	return temp;
979 }
980 
981 static int lm90_set_temp11(struct lm90_data *data, int index, long val)
982 {
983 	static struct reg {
984 		u8 high;
985 		u8 low;
986 	} reg[] = {
987 	[REMOTE_LOW] = { LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL },
988 	[REMOTE_HIGH] = { LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL },
989 	[REMOTE_OFFSET] = { LM90_REG_W_REMOTE_OFFSH, LM90_REG_W_REMOTE_OFFSL },
990 	[REMOTE2_LOW] = { LM90_REG_W_REMOTE_LOWH, LM90_REG_W_REMOTE_LOWL },
991 	[REMOTE2_HIGH] = { LM90_REG_W_REMOTE_HIGHH, LM90_REG_W_REMOTE_HIGHL }
992 	};
993 	struct i2c_client *client = data->client;
994 	struct reg *regp = &reg[index];
995 	int err;
996 
997 	/* +16 degrees offset for temp2 for the LM99 */
998 	if (data->kind == lm99 && index <= 2)
999 		val -= 16000;
1000 
1001 	if (data->kind == adt7461 || data->kind == tmp451)
1002 		data->temp11[index] = temp_to_u16_adt7461(data, val);
1003 	else if (data->kind == max6646)
1004 		data->temp11[index] = temp_to_u8(val) << 8;
1005 	else if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
1006 		data->temp11[index] = temp_to_s16(val);
1007 	else
1008 		data->temp11[index] = temp_to_s8(val) << 8;
1009 
1010 	lm90_select_remote_channel(client, data, index >= 3);
1011 	err = i2c_smbus_write_byte_data(client, regp->high,
1012 				  data->temp11[index] >> 8);
1013 	if (err < 0)
1014 		return err;
1015 	if (data->flags & LM90_HAVE_REM_LIMIT_EXT)
1016 		err = i2c_smbus_write_byte_data(client, regp->low,
1017 						data->temp11[index] & 0xff);
1018 
1019 	lm90_select_remote_channel(client, data, 0);
1020 	return err;
1021 }
1022 
1023 static int lm90_get_temp8(struct lm90_data *data, int index)
1024 {
1025 	s8 temp8 = data->temp8[index];
1026 	int temp;
1027 
1028 	if (data->kind == adt7461 || data->kind == tmp451)
1029 		temp = temp_from_u8_adt7461(data, temp8);
1030 	else if (data->kind == max6646)
1031 		temp = temp_from_u8(temp8);
1032 	else
1033 		temp = temp_from_s8(temp8);
1034 
1035 	/* +16 degrees offset for temp2 for the LM99 */
1036 	if (data->kind == lm99 && index == 3)
1037 		temp += 16000;
1038 
1039 	return temp;
1040 }
1041 
1042 static int lm90_set_temp8(struct lm90_data *data, int index, long val)
1043 {
1044 	static const u8 reg[TEMP8_REG_NUM] = {
1045 		LM90_REG_W_LOCAL_LOW,
1046 		LM90_REG_W_LOCAL_HIGH,
1047 		LM90_REG_W_LOCAL_CRIT,
1048 		LM90_REG_W_REMOTE_CRIT,
1049 		MAX6659_REG_W_LOCAL_EMERG,
1050 		MAX6659_REG_W_REMOTE_EMERG,
1051 		LM90_REG_W_REMOTE_CRIT,
1052 		MAX6659_REG_W_REMOTE_EMERG,
1053 	};
1054 	struct i2c_client *client = data->client;
1055 	int err;
1056 
1057 	/* +16 degrees offset for temp2 for the LM99 */
1058 	if (data->kind == lm99 && index == 3)
1059 		val -= 16000;
1060 
1061 	if (data->kind == adt7461 || data->kind == tmp451)
1062 		data->temp8[index] = temp_to_u8_adt7461(data, val);
1063 	else if (data->kind == max6646)
1064 		data->temp8[index] = temp_to_u8(val);
1065 	else
1066 		data->temp8[index] = temp_to_s8(val);
1067 
1068 	lm90_select_remote_channel(client, data, index >= 6);
1069 	err = i2c_smbus_write_byte_data(client, reg[index], data->temp8[index]);
1070 	lm90_select_remote_channel(client, data, 0);
1071 
1072 	return err;
1073 }
1074 
1075 static int lm90_get_temphyst(struct lm90_data *data, int index)
1076 {
1077 	int temp;
1078 
1079 	if (data->kind == adt7461 || data->kind == tmp451)
1080 		temp = temp_from_u8_adt7461(data, data->temp8[index]);
1081 	else if (data->kind == max6646)
1082 		temp = temp_from_u8(data->temp8[index]);
1083 	else
1084 		temp = temp_from_s8(data->temp8[index]);
1085 
1086 	/* +16 degrees offset for temp2 for the LM99 */
1087 	if (data->kind == lm99 && index == 3)
1088 		temp += 16000;
1089 
1090 	return temp - temp_from_s8(data->temp_hyst);
1091 }
1092 
1093 static int lm90_set_temphyst(struct lm90_data *data, long val)
1094 {
1095 	struct i2c_client *client = data->client;
1096 	int temp;
1097 	int err;
1098 
1099 	if (data->kind == adt7461 || data->kind == tmp451)
1100 		temp = temp_from_u8_adt7461(data, data->temp8[LOCAL_CRIT]);
1101 	else if (data->kind == max6646)
1102 		temp = temp_from_u8(data->temp8[LOCAL_CRIT]);
1103 	else
1104 		temp = temp_from_s8(data->temp8[LOCAL_CRIT]);
1105 
1106 	data->temp_hyst = hyst_to_reg(temp - val);
1107 	err = i2c_smbus_write_byte_data(client, LM90_REG_W_TCRIT_HYST,
1108 					data->temp_hyst);
1109 	return err;
1110 }
1111 
1112 static const u8 lm90_temp_index[3] = {
1113 	LOCAL_TEMP, REMOTE_TEMP, REMOTE2_TEMP
1114 };
1115 
1116 static const u8 lm90_temp_min_index[3] = {
1117 	LOCAL_LOW, REMOTE_LOW, REMOTE2_LOW
1118 };
1119 
1120 static const u8 lm90_temp_max_index[3] = {
1121 	LOCAL_HIGH, REMOTE_HIGH, REMOTE2_HIGH
1122 };
1123 
1124 static const u8 lm90_temp_crit_index[3] = {
1125 	LOCAL_CRIT, REMOTE_CRIT, REMOTE2_CRIT
1126 };
1127 
1128 static const u8 lm90_temp_emerg_index[3] = {
1129 	LOCAL_EMERG, REMOTE_EMERG, REMOTE2_EMERG
1130 };
1131 
1132 static const u8 lm90_min_alarm_bits[3] = { 5, 3, 11 };
1133 static const u8 lm90_max_alarm_bits[3] = { 6, 4, 12 };
1134 static const u8 lm90_crit_alarm_bits[3] = { 0, 1, 9 };
1135 static const u8 lm90_emergency_alarm_bits[3] = { 15, 13, 14 };
1136 static const u8 lm90_fault_bits[3] = { 0, 2, 10 };
1137 
1138 static int lm90_temp_read(struct device *dev, u32 attr, int channel, long *val)
1139 {
1140 	struct lm90_data *data = dev_get_drvdata(dev);
1141 	int err;
1142 
1143 	mutex_lock(&data->update_lock);
1144 	err = lm90_update_device(dev);
1145 	mutex_unlock(&data->update_lock);
1146 	if (err)
1147 		return err;
1148 
1149 	switch (attr) {
1150 	case hwmon_temp_input:
1151 		*val = lm90_get_temp11(data, lm90_temp_index[channel]);
1152 		break;
1153 	case hwmon_temp_min_alarm:
1154 		*val = (data->alarms >> lm90_min_alarm_bits[channel]) & 1;
1155 		break;
1156 	case hwmon_temp_max_alarm:
1157 		*val = (data->alarms >> lm90_max_alarm_bits[channel]) & 1;
1158 		break;
1159 	case hwmon_temp_crit_alarm:
1160 		*val = (data->alarms >> lm90_crit_alarm_bits[channel]) & 1;
1161 		break;
1162 	case hwmon_temp_emergency_alarm:
1163 		*val = (data->alarms >> lm90_emergency_alarm_bits[channel]) & 1;
1164 		break;
1165 	case hwmon_temp_fault:
1166 		*val = (data->alarms >> lm90_fault_bits[channel]) & 1;
1167 		break;
1168 	case hwmon_temp_min:
1169 		if (channel == 0)
1170 			*val = lm90_get_temp8(data,
1171 					      lm90_temp_min_index[channel]);
1172 		else
1173 			*val = lm90_get_temp11(data,
1174 					       lm90_temp_min_index[channel]);
1175 		break;
1176 	case hwmon_temp_max:
1177 		if (channel == 0)
1178 			*val = lm90_get_temp8(data,
1179 					      lm90_temp_max_index[channel]);
1180 		else
1181 			*val = lm90_get_temp11(data,
1182 					       lm90_temp_max_index[channel]);
1183 		break;
1184 	case hwmon_temp_crit:
1185 		*val = lm90_get_temp8(data, lm90_temp_crit_index[channel]);
1186 		break;
1187 	case hwmon_temp_crit_hyst:
1188 		*val = lm90_get_temphyst(data, lm90_temp_crit_index[channel]);
1189 		break;
1190 	case hwmon_temp_emergency:
1191 		*val = lm90_get_temp8(data, lm90_temp_emerg_index[channel]);
1192 		break;
1193 	case hwmon_temp_emergency_hyst:
1194 		*val = lm90_get_temphyst(data, lm90_temp_emerg_index[channel]);
1195 		break;
1196 	case hwmon_temp_offset:
1197 		*val = lm90_get_temp11(data, REMOTE_OFFSET);
1198 		break;
1199 	default:
1200 		return -EOPNOTSUPP;
1201 	}
1202 	return 0;
1203 }
1204 
1205 static int lm90_temp_write(struct device *dev, u32 attr, int channel, long val)
1206 {
1207 	struct lm90_data *data = dev_get_drvdata(dev);
1208 	int err;
1209 
1210 	mutex_lock(&data->update_lock);
1211 
1212 	err = lm90_update_device(dev);
1213 	if (err)
1214 		goto error;
1215 
1216 	switch (attr) {
1217 	case hwmon_temp_min:
1218 		if (channel == 0)
1219 			err = lm90_set_temp8(data,
1220 					      lm90_temp_min_index[channel],
1221 					      val);
1222 		else
1223 			err = lm90_set_temp11(data,
1224 					      lm90_temp_min_index[channel],
1225 					      val);
1226 		break;
1227 	case hwmon_temp_max:
1228 		if (channel == 0)
1229 			err = lm90_set_temp8(data,
1230 					     lm90_temp_max_index[channel],
1231 					     val);
1232 		else
1233 			err = lm90_set_temp11(data,
1234 					      lm90_temp_max_index[channel],
1235 					      val);
1236 		break;
1237 	case hwmon_temp_crit:
1238 		err = lm90_set_temp8(data, lm90_temp_crit_index[channel], val);
1239 		break;
1240 	case hwmon_temp_crit_hyst:
1241 		err = lm90_set_temphyst(data, val);
1242 		break;
1243 	case hwmon_temp_emergency:
1244 		err = lm90_set_temp8(data, lm90_temp_emerg_index[channel], val);
1245 		break;
1246 	case hwmon_temp_offset:
1247 		err = lm90_set_temp11(data, REMOTE_OFFSET, val);
1248 		break;
1249 	default:
1250 		err = -EOPNOTSUPP;
1251 		break;
1252 	}
1253 error:
1254 	mutex_unlock(&data->update_lock);
1255 
1256 	return err;
1257 }
1258 
1259 static umode_t lm90_temp_is_visible(const void *data, u32 attr, int channel)
1260 {
1261 	switch (attr) {
1262 	case hwmon_temp_input:
1263 	case hwmon_temp_min_alarm:
1264 	case hwmon_temp_max_alarm:
1265 	case hwmon_temp_crit_alarm:
1266 	case hwmon_temp_emergency_alarm:
1267 	case hwmon_temp_emergency_hyst:
1268 	case hwmon_temp_fault:
1269 		return 0444;
1270 	case hwmon_temp_min:
1271 	case hwmon_temp_max:
1272 	case hwmon_temp_crit:
1273 	case hwmon_temp_emergency:
1274 	case hwmon_temp_offset:
1275 		return 0644;
1276 	case hwmon_temp_crit_hyst:
1277 		if (channel == 0)
1278 			return 0644;
1279 		return 0444;
1280 	default:
1281 		return 0;
1282 	}
1283 }
1284 
1285 static int lm90_chip_read(struct device *dev, u32 attr, int channel, long *val)
1286 {
1287 	struct lm90_data *data = dev_get_drvdata(dev);
1288 	int err;
1289 
1290 	mutex_lock(&data->update_lock);
1291 	err = lm90_update_device(dev);
1292 	mutex_unlock(&data->update_lock);
1293 	if (err)
1294 		return err;
1295 
1296 	switch (attr) {
1297 	case hwmon_chip_update_interval:
1298 		*val = data->update_interval;
1299 		break;
1300 	case hwmon_chip_alarms:
1301 		*val = data->alarms;
1302 		break;
1303 	default:
1304 		return -EOPNOTSUPP;
1305 	}
1306 
1307 	return 0;
1308 }
1309 
1310 static int lm90_chip_write(struct device *dev, u32 attr, int channel, long val)
1311 {
1312 	struct lm90_data *data = dev_get_drvdata(dev);
1313 	struct i2c_client *client = data->client;
1314 	int err;
1315 
1316 	mutex_lock(&data->update_lock);
1317 
1318 	err = lm90_update_device(dev);
1319 	if (err)
1320 		goto error;
1321 
1322 	switch (attr) {
1323 	case hwmon_chip_update_interval:
1324 		err = lm90_set_convrate(client, data,
1325 					clamp_val(val, 0, 100000));
1326 		break;
1327 	default:
1328 		err = -EOPNOTSUPP;
1329 		break;
1330 	}
1331 error:
1332 	mutex_unlock(&data->update_lock);
1333 
1334 	return err;
1335 }
1336 
1337 static umode_t lm90_chip_is_visible(const void *data, u32 attr, int channel)
1338 {
1339 	switch (attr) {
1340 	case hwmon_chip_update_interval:
1341 		return 0644;
1342 	case hwmon_chip_alarms:
1343 		return 0444;
1344 	default:
1345 		return 0;
1346 	}
1347 }
1348 
1349 static int lm90_read(struct device *dev, enum hwmon_sensor_types type,
1350 		     u32 attr, int channel, long *val)
1351 {
1352 	switch (type) {
1353 	case hwmon_chip:
1354 		return lm90_chip_read(dev, attr, channel, val);
1355 	case hwmon_temp:
1356 		return lm90_temp_read(dev, attr, channel, val);
1357 	default:
1358 		return -EOPNOTSUPP;
1359 	}
1360 }
1361 
1362 static int lm90_write(struct device *dev, enum hwmon_sensor_types type,
1363 		      u32 attr, int channel, long val)
1364 {
1365 	switch (type) {
1366 	case hwmon_chip:
1367 		return lm90_chip_write(dev, attr, channel, val);
1368 	case hwmon_temp:
1369 		return lm90_temp_write(dev, attr, channel, val);
1370 	default:
1371 		return -EOPNOTSUPP;
1372 	}
1373 }
1374 
1375 static umode_t lm90_is_visible(const void *data, enum hwmon_sensor_types type,
1376 			       u32 attr, int channel)
1377 {
1378 	switch (type) {
1379 	case hwmon_chip:
1380 		return lm90_chip_is_visible(data, attr, channel);
1381 	case hwmon_temp:
1382 		return lm90_temp_is_visible(data, attr, channel);
1383 	default:
1384 		return 0;
1385 	}
1386 }
1387 
1388 /* Return 0 if detection is successful, -ENODEV otherwise */
1389 static int lm90_detect(struct i2c_client *client,
1390 		       struct i2c_board_info *info)
1391 {
1392 	struct i2c_adapter *adapter = client->adapter;
1393 	int address = client->addr;
1394 	const char *name = NULL;
1395 	int man_id, chip_id, config1, config2, convrate;
1396 
1397 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
1398 		return -ENODEV;
1399 
1400 	/* detection and identification */
1401 	man_id = i2c_smbus_read_byte_data(client, LM90_REG_R_MAN_ID);
1402 	chip_id = i2c_smbus_read_byte_data(client, LM90_REG_R_CHIP_ID);
1403 	config1 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG1);
1404 	convrate = i2c_smbus_read_byte_data(client, LM90_REG_R_CONVRATE);
1405 	if (man_id < 0 || chip_id < 0 || config1 < 0 || convrate < 0)
1406 		return -ENODEV;
1407 
1408 	if (man_id == 0x01 || man_id == 0x5C || man_id == 0x41) {
1409 		config2 = i2c_smbus_read_byte_data(client, LM90_REG_R_CONFIG2);
1410 		if (config2 < 0)
1411 			return -ENODEV;
1412 	} else
1413 		config2 = 0;		/* Make compiler happy */
1414 
1415 	if ((address == 0x4C || address == 0x4D)
1416 	 && man_id == 0x01) { /* National Semiconductor */
1417 		if ((config1 & 0x2A) == 0x00
1418 		 && (config2 & 0xF8) == 0x00
1419 		 && convrate <= 0x09) {
1420 			if (address == 0x4C
1421 			 && (chip_id & 0xF0) == 0x20) { /* LM90 */
1422 				name = "lm90";
1423 			} else
1424 			if ((chip_id & 0xF0) == 0x30) { /* LM89/LM99 */
1425 				name = "lm99";
1426 				dev_info(&adapter->dev,
1427 					 "Assuming LM99 chip at 0x%02x\n",
1428 					 address);
1429 				dev_info(&adapter->dev,
1430 					 "If it is an LM89, instantiate it "
1431 					 "with the new_device sysfs "
1432 					 "interface\n");
1433 			} else
1434 			if (address == 0x4C
1435 			 && (chip_id & 0xF0) == 0x10) { /* LM86 */
1436 				name = "lm86";
1437 			}
1438 		}
1439 	} else
1440 	if ((address == 0x4C || address == 0x4D)
1441 	 && man_id == 0x41) { /* Analog Devices */
1442 		if ((chip_id & 0xF0) == 0x40 /* ADM1032 */
1443 		 && (config1 & 0x3F) == 0x00
1444 		 && convrate <= 0x0A) {
1445 			name = "adm1032";
1446 			/*
1447 			 * The ADM1032 supports PEC, but only if combined
1448 			 * transactions are not used.
1449 			 */
1450 			if (i2c_check_functionality(adapter,
1451 						    I2C_FUNC_SMBUS_BYTE))
1452 				info->flags |= I2C_CLIENT_PEC;
1453 		} else
1454 		if (chip_id == 0x51 /* ADT7461 */
1455 		 && (config1 & 0x1B) == 0x00
1456 		 && convrate <= 0x0A) {
1457 			name = "adt7461";
1458 		} else
1459 		if (chip_id == 0x57 /* ADT7461A, NCT1008 */
1460 		 && (config1 & 0x1B) == 0x00
1461 		 && convrate <= 0x0A) {
1462 			name = "adt7461a";
1463 		}
1464 	} else
1465 	if (man_id == 0x4D) { /* Maxim */
1466 		int emerg, emerg2, status2;
1467 
1468 		/*
1469 		 * We read MAX6659_REG_R_REMOTE_EMERG twice, and re-read
1470 		 * LM90_REG_R_MAN_ID in between. If MAX6659_REG_R_REMOTE_EMERG
1471 		 * exists, both readings will reflect the same value. Otherwise,
1472 		 * the readings will be different.
1473 		 */
1474 		emerg = i2c_smbus_read_byte_data(client,
1475 						 MAX6659_REG_R_REMOTE_EMERG);
1476 		man_id = i2c_smbus_read_byte_data(client,
1477 						  LM90_REG_R_MAN_ID);
1478 		emerg2 = i2c_smbus_read_byte_data(client,
1479 						  MAX6659_REG_R_REMOTE_EMERG);
1480 		status2 = i2c_smbus_read_byte_data(client,
1481 						   MAX6696_REG_R_STATUS2);
1482 		if (emerg < 0 || man_id < 0 || emerg2 < 0 || status2 < 0)
1483 			return -ENODEV;
1484 
1485 		/*
1486 		 * The MAX6657, MAX6658 and MAX6659 do NOT have a chip_id
1487 		 * register. Reading from that address will return the last
1488 		 * read value, which in our case is those of the man_id
1489 		 * register. Likewise, the config1 register seems to lack a
1490 		 * low nibble, so the value will be those of the previous
1491 		 * read, so in our case those of the man_id register.
1492 		 * MAX6659 has a third set of upper temperature limit registers.
1493 		 * Those registers also return values on MAX6657 and MAX6658,
1494 		 * thus the only way to detect MAX6659 is by its address.
1495 		 * For this reason it will be mis-detected as MAX6657 if its
1496 		 * address is 0x4C.
1497 		 */
1498 		if (chip_id == man_id
1499 		 && (address == 0x4C || address == 0x4D || address == 0x4E)
1500 		 && (config1 & 0x1F) == (man_id & 0x0F)
1501 		 && convrate <= 0x09) {
1502 			if (address == 0x4C)
1503 				name = "max6657";
1504 			else
1505 				name = "max6659";
1506 		} else
1507 		/*
1508 		 * Even though MAX6695 and MAX6696 do not have a chip ID
1509 		 * register, reading it returns 0x01. Bit 4 of the config1
1510 		 * register is unused and should return zero when read. Bit 0 of
1511 		 * the status2 register is unused and should return zero when
1512 		 * read.
1513 		 *
1514 		 * MAX6695 and MAX6696 have an additional set of temperature
1515 		 * limit registers. We can detect those chips by checking if
1516 		 * one of those registers exists.
1517 		 */
1518 		if (chip_id == 0x01
1519 		 && (config1 & 0x10) == 0x00
1520 		 && (status2 & 0x01) == 0x00
1521 		 && emerg == emerg2
1522 		 && convrate <= 0x07) {
1523 			name = "max6696";
1524 		} else
1525 		/*
1526 		 * The chip_id register of the MAX6680 and MAX6681 holds the
1527 		 * revision of the chip. The lowest bit of the config1 register
1528 		 * is unused and should return zero when read, so should the
1529 		 * second to last bit of config1 (software reset).
1530 		 */
1531 		if (chip_id == 0x01
1532 		 && (config1 & 0x03) == 0x00
1533 		 && convrate <= 0x07) {
1534 			name = "max6680";
1535 		} else
1536 		/*
1537 		 * The chip_id register of the MAX6646/6647/6649 holds the
1538 		 * revision of the chip. The lowest 6 bits of the config1
1539 		 * register are unused and should return zero when read.
1540 		 */
1541 		if (chip_id == 0x59
1542 		 && (config1 & 0x3f) == 0x00
1543 		 && convrate <= 0x07) {
1544 			name = "max6646";
1545 		}
1546 	} else
1547 	if (address == 0x4C
1548 	 && man_id == 0x5C) { /* Winbond/Nuvoton */
1549 		if ((config1 & 0x2A) == 0x00
1550 		 && (config2 & 0xF8) == 0x00) {
1551 			if (chip_id == 0x01 /* W83L771W/G */
1552 			 && convrate <= 0x09) {
1553 				name = "w83l771";
1554 			} else
1555 			if ((chip_id & 0xFE) == 0x10 /* W83L771AWG/ASG */
1556 			 && convrate <= 0x08) {
1557 				name = "w83l771";
1558 			}
1559 		}
1560 	} else
1561 	if (address >= 0x48 && address <= 0x4F
1562 	 && man_id == 0xA1) { /*  NXP Semiconductor/Philips */
1563 		if (chip_id == 0x00
1564 		 && (config1 & 0x2A) == 0x00
1565 		 && (config2 & 0xFE) == 0x00
1566 		 && convrate <= 0x09) {
1567 			name = "sa56004";
1568 		}
1569 	} else
1570 	if ((address == 0x4C || address == 0x4D)
1571 	 && man_id == 0x47) { /* GMT */
1572 		if (chip_id == 0x01 /* G781 */
1573 		 && (config1 & 0x3F) == 0x00
1574 		 && convrate <= 0x08)
1575 			name = "g781";
1576 	} else
1577 	if (address == 0x4C
1578 	 && man_id == 0x55) { /* Texas Instruments */
1579 		int local_ext;
1580 
1581 		local_ext = i2c_smbus_read_byte_data(client,
1582 						     TMP451_REG_R_LOCAL_TEMPL);
1583 
1584 		if (chip_id == 0x00 /* TMP451 */
1585 		 && (config1 & 0x1B) == 0x00
1586 		 && convrate <= 0x09
1587 		 && (local_ext & 0x0F) == 0x00)
1588 			name = "tmp451";
1589 	}
1590 
1591 	if (!name) { /* identification failed */
1592 		dev_dbg(&adapter->dev,
1593 			"Unsupported chip at 0x%02x (man_id=0x%02X, "
1594 			"chip_id=0x%02X)\n", address, man_id, chip_id);
1595 		return -ENODEV;
1596 	}
1597 
1598 	strlcpy(info->type, name, I2C_NAME_SIZE);
1599 
1600 	return 0;
1601 }
1602 
1603 static void lm90_restore_conf(void *_data)
1604 {
1605 	struct lm90_data *data = _data;
1606 	struct i2c_client *client = data->client;
1607 
1608 	/* Restore initial configuration */
1609 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONVRATE,
1610 				  data->convrate_orig);
1611 	i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
1612 				  data->config_orig);
1613 }
1614 
1615 static int lm90_init_client(struct i2c_client *client, struct lm90_data *data)
1616 {
1617 	int config, convrate;
1618 
1619 	convrate = lm90_read_reg(client, LM90_REG_R_CONVRATE);
1620 	if (convrate < 0)
1621 		return convrate;
1622 	data->convrate_orig = convrate;
1623 
1624 	/*
1625 	 * Start the conversions.
1626 	 */
1627 	lm90_set_convrate(client, data, 500);	/* 500ms; 2Hz conversion rate */
1628 	config = lm90_read_reg(client, LM90_REG_R_CONFIG1);
1629 	if (config < 0)
1630 		return config;
1631 	data->config_orig = config;
1632 
1633 	/* Check Temperature Range Select */
1634 	if (data->kind == adt7461 || data->kind == tmp451) {
1635 		if (config & 0x04)
1636 			data->flags |= LM90_FLAG_ADT7461_EXT;
1637 	}
1638 
1639 	/*
1640 	 * Put MAX6680/MAX8881 into extended resolution (bit 0x10,
1641 	 * 0.125 degree resolution) and range (0x08, extend range
1642 	 * to -64 degree) mode for the remote temperature sensor.
1643 	 */
1644 	if (data->kind == max6680)
1645 		config |= 0x18;
1646 
1647 	/*
1648 	 * Select external channel 0 for max6695/96
1649 	 */
1650 	if (data->kind == max6696)
1651 		config &= ~0x08;
1652 
1653 	config &= 0xBF;	/* run */
1654 	if (config != data->config_orig) /* Only write if changed */
1655 		i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
1656 
1657 	return devm_add_action_or_reset(&client->dev, lm90_restore_conf, data);
1658 }
1659 
1660 static bool lm90_is_tripped(struct i2c_client *client, u16 *status)
1661 {
1662 	struct lm90_data *data = i2c_get_clientdata(client);
1663 	int st, st2 = 0;
1664 
1665 	st = lm90_read_reg(client, LM90_REG_R_STATUS);
1666 	if (st < 0)
1667 		return false;
1668 
1669 	if (data->kind == max6696) {
1670 		st2 = lm90_read_reg(client, MAX6696_REG_R_STATUS2);
1671 		if (st2 < 0)
1672 			return false;
1673 	}
1674 
1675 	*status = st | (st2 << 8);
1676 
1677 	if ((st & 0x7f) == 0 && (st2 & 0xfe) == 0)
1678 		return false;
1679 
1680 	if ((st & (LM90_STATUS_LLOW | LM90_STATUS_LHIGH | LM90_STATUS_LTHRM)) ||
1681 	    (st2 & MAX6696_STATUS2_LOT2))
1682 		dev_warn(&client->dev,
1683 			 "temp%d out of range, please check!\n", 1);
1684 	if ((st & (LM90_STATUS_RLOW | LM90_STATUS_RHIGH | LM90_STATUS_RTHRM)) ||
1685 	    (st2 & MAX6696_STATUS2_ROT2))
1686 		dev_warn(&client->dev,
1687 			 "temp%d out of range, please check!\n", 2);
1688 	if (st & LM90_STATUS_ROPEN)
1689 		dev_warn(&client->dev,
1690 			 "temp%d diode open, please check!\n", 2);
1691 	if (st2 & (MAX6696_STATUS2_R2LOW | MAX6696_STATUS2_R2HIGH |
1692 		   MAX6696_STATUS2_R2THRM | MAX6696_STATUS2_R2OT2))
1693 		dev_warn(&client->dev,
1694 			 "temp%d out of range, please check!\n", 3);
1695 	if (st2 & MAX6696_STATUS2_R2OPEN)
1696 		dev_warn(&client->dev,
1697 			 "temp%d diode open, please check!\n", 3);
1698 
1699 	return true;
1700 }
1701 
1702 static irqreturn_t lm90_irq_thread(int irq, void *dev_id)
1703 {
1704 	struct i2c_client *client = dev_id;
1705 	u16 status;
1706 
1707 	if (lm90_is_tripped(client, &status))
1708 		return IRQ_HANDLED;
1709 	else
1710 		return IRQ_NONE;
1711 }
1712 
1713 static void lm90_remove_pec(void *dev)
1714 {
1715 	device_remove_file(dev, &dev_attr_pec);
1716 }
1717 
1718 static void lm90_regulator_disable(void *regulator)
1719 {
1720 	regulator_disable(regulator);
1721 }
1722 
1723 static const u32 lm90_chip_config[] = {
1724 	HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL | HWMON_C_ALARMS,
1725 	0
1726 };
1727 
1728 static const struct hwmon_channel_info lm90_chip_info = {
1729 	.type = hwmon_chip,
1730 	.config = lm90_chip_config,
1731 };
1732 
1733 
1734 static const struct hwmon_ops lm90_ops = {
1735 	.is_visible = lm90_is_visible,
1736 	.read = lm90_read,
1737 	.write = lm90_write,
1738 };
1739 
1740 static int lm90_probe(struct i2c_client *client,
1741 		      const struct i2c_device_id *id)
1742 {
1743 	struct device *dev = &client->dev;
1744 	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
1745 	struct hwmon_channel_info *info;
1746 	struct regulator *regulator;
1747 	struct device *hwmon_dev;
1748 	struct lm90_data *data;
1749 	int err;
1750 
1751 	regulator = devm_regulator_get(dev, "vcc");
1752 	if (IS_ERR(regulator))
1753 		return PTR_ERR(regulator);
1754 
1755 	err = regulator_enable(regulator);
1756 	if (err < 0) {
1757 		dev_err(dev, "Failed to enable regulator: %d\n", err);
1758 		return err;
1759 	}
1760 
1761 	err = devm_add_action_or_reset(dev, lm90_regulator_disable, regulator);
1762 	if (err)
1763 		return err;
1764 
1765 	data = devm_kzalloc(dev, sizeof(struct lm90_data), GFP_KERNEL);
1766 	if (!data)
1767 		return -ENOMEM;
1768 
1769 	data->client = client;
1770 	i2c_set_clientdata(client, data);
1771 	mutex_init(&data->update_lock);
1772 
1773 	/* Set the device type */
1774 	if (client->dev.of_node)
1775 		data->kind = (enum chips)of_device_get_match_data(&client->dev);
1776 	else
1777 		data->kind = id->driver_data;
1778 	if (data->kind == adm1032) {
1779 		if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
1780 			client->flags &= ~I2C_CLIENT_PEC;
1781 	}
1782 
1783 	/*
1784 	 * Different devices have different alarm bits triggering the
1785 	 * ALERT# output
1786 	 */
1787 	data->alert_alarms = lm90_params[data->kind].alert_alarms;
1788 
1789 	/* Set chip capabilities */
1790 	data->flags = lm90_params[data->kind].flags;
1791 
1792 	data->chip.ops = &lm90_ops;
1793 	data->chip.info = data->info;
1794 
1795 	data->info[0] = &lm90_chip_info;
1796 	data->info[1] = &data->temp_info;
1797 
1798 	info = &data->temp_info;
1799 	info->type = hwmon_temp;
1800 	info->config = data->channel_config;
1801 
1802 	data->channel_config[0] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
1803 		HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
1804 		HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM;
1805 	data->channel_config[1] = HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
1806 		HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
1807 		HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT;
1808 
1809 	if (data->flags & LM90_HAVE_OFFSET)
1810 		data->channel_config[1] |= HWMON_T_OFFSET;
1811 
1812 	if (data->flags & LM90_HAVE_EMERGENCY) {
1813 		data->channel_config[0] |= HWMON_T_EMERGENCY |
1814 			HWMON_T_EMERGENCY_HYST;
1815 		data->channel_config[1] |= HWMON_T_EMERGENCY |
1816 			HWMON_T_EMERGENCY_HYST;
1817 	}
1818 
1819 	if (data->flags & LM90_HAVE_EMERGENCY_ALARM) {
1820 		data->channel_config[0] |= HWMON_T_EMERGENCY_ALARM;
1821 		data->channel_config[1] |= HWMON_T_EMERGENCY_ALARM;
1822 	}
1823 
1824 	if (data->flags & LM90_HAVE_TEMP3) {
1825 		data->channel_config[2] = HWMON_T_INPUT |
1826 			HWMON_T_MIN | HWMON_T_MAX |
1827 			HWMON_T_CRIT | HWMON_T_CRIT_HYST |
1828 			HWMON_T_EMERGENCY | HWMON_T_EMERGENCY_HYST |
1829 			HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
1830 			HWMON_T_CRIT_ALARM | HWMON_T_EMERGENCY_ALARM |
1831 			HWMON_T_FAULT;
1832 	}
1833 
1834 	data->reg_local_ext = lm90_params[data->kind].reg_local_ext;
1835 
1836 	/* Set maximum conversion rate */
1837 	data->max_convrate = lm90_params[data->kind].max_convrate;
1838 
1839 	/* Initialize the LM90 chip */
1840 	err = lm90_init_client(client, data);
1841 	if (err < 0) {
1842 		dev_err(dev, "Failed to initialize device\n");
1843 		return err;
1844 	}
1845 
1846 	/*
1847 	 * The 'pec' attribute is attached to the i2c device and thus created
1848 	 * separately.
1849 	 */
1850 	if (client->flags & I2C_CLIENT_PEC) {
1851 		err = device_create_file(dev, &dev_attr_pec);
1852 		if (err)
1853 			return err;
1854 		err = devm_add_action_or_reset(dev, lm90_remove_pec, dev);
1855 		if (err)
1856 			return err;
1857 	}
1858 
1859 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
1860 							 data, &data->chip,
1861 							 NULL);
1862 	if (IS_ERR(hwmon_dev))
1863 		return PTR_ERR(hwmon_dev);
1864 
1865 	if (client->irq) {
1866 		dev_dbg(dev, "IRQ: %d\n", client->irq);
1867 		err = devm_request_threaded_irq(dev, client->irq,
1868 						NULL, lm90_irq_thread,
1869 						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
1870 						"lm90", client);
1871 		if (err < 0) {
1872 			dev_err(dev, "cannot request IRQ %d\n", client->irq);
1873 			return err;
1874 		}
1875 	}
1876 
1877 	return 0;
1878 }
1879 
1880 static void lm90_alert(struct i2c_client *client, enum i2c_alert_protocol type,
1881 		       unsigned int flag)
1882 {
1883 	u16 alarms;
1884 
1885 	if (type != I2C_PROTOCOL_SMBUS_ALERT)
1886 		return;
1887 
1888 	if (lm90_is_tripped(client, &alarms)) {
1889 		/*
1890 		 * Disable ALERT# output, because these chips don't implement
1891 		 * SMBus alert correctly; they should only hold the alert line
1892 		 * low briefly.
1893 		 */
1894 		struct lm90_data *data = i2c_get_clientdata(client);
1895 
1896 		if ((data->flags & LM90_HAVE_BROKEN_ALERT) &&
1897 		    (alarms & data->alert_alarms)) {
1898 			int config;
1899 
1900 			dev_dbg(&client->dev, "Disabling ALERT#\n");
1901 			config = lm90_read_reg(client, LM90_REG_R_CONFIG1);
1902 			if (config >= 0)
1903 				i2c_smbus_write_byte_data(client,
1904 							  LM90_REG_W_CONFIG1,
1905 							  config | 0x80);
1906 		}
1907 	} else {
1908 		dev_info(&client->dev, "Everything OK\n");
1909 	}
1910 }
1911 
1912 static struct i2c_driver lm90_driver = {
1913 	.class		= I2C_CLASS_HWMON,
1914 	.driver = {
1915 		.name	= "lm90",
1916 		.of_match_table = of_match_ptr(lm90_of_match),
1917 	},
1918 	.probe		= lm90_probe,
1919 	.alert		= lm90_alert,
1920 	.id_table	= lm90_id,
1921 	.detect		= lm90_detect,
1922 	.address_list	= normal_i2c,
1923 };
1924 
1925 module_i2c_driver(lm90_driver);
1926 
1927 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
1928 MODULE_DESCRIPTION("LM90/ADM1032 driver");
1929 MODULE_LICENSE("GPL");
1930